Differences in Prevalence and Severity of Liver Disease Between Lateral Tunnel and Extracardiac Conduit Fontan

BACKGROUND: Recent studies suggest differences in liver disease severity based on the type of total cavopulmonary connection (TCPC). OBJECTIVES: The purpose of this study was to compare the severity and progression of liver disease between patients with extracardiac conduit (ECC) vs lateral tunnel (LT) using 2 separate cohorts: i) TCPC at the initial Fontan operation (primary-TCPC cohort) and ii) Fontan conversion (FC) to TCPC (FC-TCPC cohort). METHOD: This is a retrospective study of adults with TCPC (ECC [N = 62, 46%]; LT [N = 73,54%). Liver disease severity was assessed at baseline using biomarkers (model for end-stage liver disease excluding international normalized ratio, Fibrosis-4 [FIB-4], aspartate aminotransferase to platelet ratio index [APRI]), and progression of liver disease was assessed as temporal change in biomarkers at 3, 5, and 7 years. RESULTS: In the primary-TCPC cohort (ECC [N = 62,46%]; LT [N = 73,54%), patients with ECC had a higher prevalence of cirrhosis (27% vs 12%; P = 0.03) and worse disease severity at baseline (APRI 0.46 [0.34;0.61] vs 0.39 [0.29;0.52], P < 0.001; FIB-4 (0.89 [0.59;1.12] vs 0.76 [0.31;0.99], P = 0.009) compared to LT. Both groups had progression of liver disease (temporal increase in biomarker levels), but the ECC group had a greater temporal increase in biomarker levels resulting in a higher relative increase in model for end-stage liver disease excluding international normalized ratio, FIB-4, and APRI. There were no significant differences in prevalence and severity of liver disease at baseline, or liver disease progression during follow-up between patients with ECC vs LT in the FC-TCPC group. CONCLUSIONS: ECC was associated with a higher prevalence and worse severity of liver disease at baseline, and greater disease progression during follow-up compared to those with LT. Further studies are required to determine the optimal strategies for the management of liver disease in patients with ECC.